A legacy of change : historic human impact on vegetation in the Arizona borderlands

Description :
The A. believes that the natural vegetation of Southern Arizona underwent change since 1970 as a result of human impacts on the plant cover, mainly through livestock grazing, fire suppression, agriculture and logging. Discounts the role of climatic change. Lines of evidence used include standard historical accounts, landscape photography taken at different time periods, land surveyors' field notes, and high altitude vertical aerial photography. - (DWG)